Use of an extruded microalgae and flaxseed blend product and its effects on ruminal fermentation and nutrient disappearance

Abstract

Omega-3 fatty acid supplementation has been researched in both the dairy and beef cattle sectors since these fatty acids are considered essential to animal health. Naturally Better Omega-3 Technologies (Manhattan, Kansas) has developed a supplement consisting of an extruded blend of flaxseed and microalgae (FAB; greatOplus) that is fed to livestock to supplement α-linolenic acid (ALA). Our objective was to evaluate how ruminal microbes alter composition of the fatty acids in the FAB, and their post ruminal disappearance. Eleven steers fitted with ruminal and duodenal cannulas were housed in a facility equipped with the Insentec feed and water monitoring system (Hokofarm, Emmeloord the Netherlands). A cross over design was utilized and treatments included a control diet without ALA supplementation and a treatment diet with supplementation of the FAB at 10 % of the diet dry matter. Duodenal flow of total fatty acids (g) was greater (P=0.002) for cattle supplemented with FAB than for non-supplemented cattle. In particular, duodenal flow of ALA (g) was observed to be four times greater (6.3 g/d vs 1.6 g/d; P=0.001) for steers fed the FAB supplement compared to steers fed the control diet. The inconsistent amount of unsaturated fatty acids consumed compared to the apparent duodenal flow of unsaturated fatty acids, indicates that substantial biohydrogenation of the FAB occurred in the rumen. Supplementing steers with FAB increased the apparent duodenal flow of ALA however, substantial biohydrogenation of the ALA likely occurs and must be taken into consideration when feeding this FAB to increase ALA consumption in cattle.